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    <h3>Editing: CachingFileAnalyser.php</h3>
    <textarea name="content" rows="20" cols="80">&lt;?php declare(strict_types=1);
/*
 * This file is part of phpunit/php-code-coverage.
 *
 * (c) Sebastian Bergmann &lt;sebastian@phpunit.de&gt;
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
namespace SebastianBergmann\CodeCoverage\StaticAnalysis;

use function file_get_contents;
use function file_put_contents;
use function implode;
use function is_file;
use function md5;
use function serialize;
use function unserialize;
use SebastianBergmann\CodeCoverage\Util\Filesystem;
use SebastianBergmann\FileIterator\Facade as FileIteratorFacade;

/**
 * @internal This class is not covered by the backward compatibility promise for phpunit/php-code-coverage
 */
final class CachingFileAnalyser implements FileAnalyser
{
    /**
     * @var ?string
     */
    private static $cacheVersion;

    /**
     * @var string
     */
    private $directory;

    /**
     * @var FileAnalyser
     */
    private $analyser;

    /**
     * @var bool
     */
    private $useAnnotationsForIgnoringCode;

    /**
     * @var bool
     */
    private $ignoreDeprecatedCode;

    /**
     * @var array
     */
    private $cache = [];

    public function __construct(string $directory, FileAnalyser $analyser, bool $useAnnotationsForIgnoringCode, bool $ignoreDeprecatedCode)
    {
        Filesystem::createDirectory($directory);

        $this-&gt;analyser                      = $analyser;
        $this-&gt;directory                     = $directory;
        $this-&gt;useAnnotationsForIgnoringCode = $useAnnotationsForIgnoringCode;
        $this-&gt;ignoreDeprecatedCode          = $ignoreDeprecatedCode;
    }

    public function classesIn(string $filename): array
    {
        if (!isset($this-&gt;cache[$filename])) {
            $this-&gt;process($filename);
        }

        return $this-&gt;cache[$filename]['classesIn'];
    }

    public function traitsIn(string $filename): array
    {
        if (!isset($this-&gt;cache[$filename])) {
            $this-&gt;process($filename);
        }

        return $this-&gt;cache[$filename]['traitsIn'];
    }

    public function functionsIn(string $filename): array
    {
        if (!isset($this-&gt;cache[$filename])) {
            $this-&gt;process($filename);
        }

        return $this-&gt;cache[$filename]['functionsIn'];
    }

    /**
     * @psalm-return array{linesOfCode: int, commentLinesOfCode: int, nonCommentLinesOfCode: int}
     */
    public function linesOfCodeFor(string $filename): array
    {
        if (!isset($this-&gt;cache[$filename])) {
            $this-&gt;process($filename);
        }

        return $this-&gt;cache[$filename]['linesOfCodeFor'];
    }

    public function executableLinesIn(string $filename): array
    {
        if (!isset($this-&gt;cache[$filename])) {
            $this-&gt;process($filename);
        }

        return $this-&gt;cache[$filename]['executableLinesIn'];
    }

    public function ignoredLinesFor(string $filename): array
    {
        if (!isset($this-&gt;cache[$filename])) {
            $this-&gt;process($filename);
        }

        return $this-&gt;cache[$filename]['ignoredLinesFor'];
    }

    public function process(string $filename): void
    {
        $cache = $this-&gt;read($filename);

        if ($cache !== false) {
            $this-&gt;cache[$filename] = $cache;

            return;
        }

        $this-&gt;cache[$filename] = [
            'classesIn'         =&gt; $this-&gt;analyser-&gt;classesIn($filename),
            'traitsIn'          =&gt; $this-&gt;analyser-&gt;traitsIn($filename),
            'functionsIn'       =&gt; $this-&gt;analyser-&gt;functionsIn($filename),
            'linesOfCodeFor'    =&gt; $this-&gt;analyser-&gt;linesOfCodeFor($filename),
            'ignoredLinesFor'   =&gt; $this-&gt;analyser-&gt;ignoredLinesFor($filename),
            'executableLinesIn' =&gt; $this-&gt;analyser-&gt;executableLinesIn($filename),
        ];

        $this-&gt;write($filename, $this-&gt;cache[$filename]);
    }

    /**
     * @return mixed
     */
    private function read(string $filename)
    {
        $cacheFile = $this-&gt;cacheFile($filename);

        if (!is_file($cacheFile)) {
            return false;
        }

        return unserialize(
            file_get_contents($cacheFile),
            ['allowed_classes' =&gt; false]
        );
    }

    /**
     * @param mixed $data
     */
    private function write(string $filename, $data): void
    {
        file_put_contents(
            $this-&gt;cacheFile($filename),
            serialize($data)
        );
    }

    private function cacheFile(string $filename): string
    {
        $cacheKey = md5(
            implode(
                &quot;\0&quot;,
                [
                    $filename,
                    file_get_contents($filename),
                    self::cacheVersion(),
                    $this-&gt;useAnnotationsForIgnoringCode,
                    $this-&gt;ignoreDeprecatedCode,
                ]
            )
        );

        return $this-&gt;directory . DIRECTORY_SEPARATOR . $cacheKey;
    }

    private static function cacheVersion(): string
    {
        if (self::$cacheVersion !== null) {
            return self::$cacheVersion;
        }

        $buffer = [];

        foreach ((new FileIteratorFacade)-&gt;getFilesAsArray(__DIR__, '.php') as $file) {
            $buffer[] = $file;
            $buffer[] = file_get_contents($file);
        }

        self::$cacheVersion = md5(implode(&quot;\0&quot;, $buffer));

        return self::$cacheVersion;
    }
}
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